New cloud storage services allow groups of researchers to share, transfer and synchronize data in simple but powerful ways. Large-scale synchronization and sharing capabilities (typically above the 1-PB mark) are an opportunity for innovative applications in scientific and technical areas, allowing for new forms of collaboration and to achieve results faster and more effectively. This is also a unique opportunity for IT departments to renew service offerings and to boost infrastructure by federating data repositories across collaborating sites and proposing/hosting new applications. The objective of this workshop is to share experiences and progress in cloud storage services. The usage of recently deployed services in the scientific community is rapidly expanding. Users are actively interested in new solutions for their growing data needs: new tools and enhanced data sharing capabilities enable new solutions. At the same time, the technology space is quickly evolving and many research institutes, service providers, software development teams and companies look into different approaches in the area of Cloud Services for Synchronisation and Sharing. In the workshop we will review the state-of-the-art technologies for Cloud Services for Synchronisation and Sharing and evaluate the experience in running such services for technical and scientific communities. We especially invite user communities to report on current and planned usage, novel applications and innovative workflows. We invite technology and service providers to present their services, including the evolution of existing implementations towards Cloud Storage Services.